Understanding PET Modification Methods in One Article
1、Filling modification of PET
Filler modification is one of the most direct and effective ways to comprehensively improve the performance of materials by using inorganic components that are completely different from the properties of the polymer matrix.
- Nanoparticle-modified PET
Currently, research on the modification of PET composite materials using nanoparticles is very advanced. Ke et al. used layered clay to modify PET and obtained PET/clay nanocomposites using intercalated polymerization. The results of the study showed that when the clay content was 5wt%, the heat deformation temperature of the composite material increased by about 20℃~50℃ compared to pure PET; and the modulus of the composite material increased by about 2 times compared to PET.
- Glass fiber modified PET
Compared to nanoparticles, micron-sized glass fibers (GF) have prominent advantages in terms of cost and controllability, making them widely used for filling modified polymer materials.
- Blending modification of PET
Polymer alloys or blends with new properties can be formed by melt blending two or more polymers, including PET, in appropriate proportions under certain temperature and shear stress conditions. The compatibility between polymers is crucial for the preparation of such polymer blends.
- Polyethylene Modified PET
PET and PE have significant differences in their chemical structures and are not compatible. Research on simple binary blends of the two has found that in order to improve the impact resistance of PET through polymer blending, it is necessary to improve the compatibility of the two through compatibilization methods. In the blend system of HDPE and PET, the impact strength is improved when EVA and EAA systems are added.
The PET and PP blend forms an alloy that combines the advantages of both, resulting in improved performance. For example, PET enhances the heat resistance of PP, while PP reduces the sensitivity of PET to moisture. Without the presence of a compatibilizer, the blend of PET and PP has weak interfacial bonding and poor mechanical properties.
PET/PS is an incompatible system and requires the addition of a compatibilizer to achieve blend compatibility. Research has found that adding a reactive compatibilizer, such as poly(styrene-co-glycidyl methacrylate) (P(S-GMA)), to the PET/PS blend system results in a PET/PS/P(S-GMA) blend with improved interface bonding and enhanced mechanical properties.
- Modified PET
PBT is a new type of engineering plastic that rapidly developed in the 1970s. It has better mechanical properties than PET and good toughness, and can be molded. However, its heat resistance and flowability are not as good as PET, and it is also more expensive. According to Teijin Corporation, adding 0.5% talcum powder as a nucleating agent in the blend of the two can improve the impact resistance and reduce the molding shrinkage.
PC has good mechanical properties, good toughness, and a high glass transition temperature, but its flowability and resistance to aging are poor. Blending PET and PC can improve the impact strength. The blend of the two has been industrialized abroad and has a wide range of applications in automotive parts.
- Toughening modification of elastic polymer PET
ABS is one of the most widely used polymers currently. It not only has good toughness but also has better overall performance than HIPS. Blending PET with ABS can improve the impact strength of PET.
In the study, it was found that the relative molecular weight of PET in the blend is highly sensitive to processing temperature. The hydrolysis of PET chains is related to the thermal and residual catalyst impurities in ABS. The decrease in relative molecular weight of PET leads to significant loss in impact performance and ultimate elongation, but has no effect on modulus and flexural strength.